The invention is based on a wiper apparatus. In a known wiper apparatus of this type (German patent disclosure DE 23 13 689 A1), the wiper blade, or its coupling part, that belongs to the wiper apparatus has a guide channel that is open toward a base body of the wiper strip, and in this channel, a hairpin-shaped securing spring is displaceable between a mounting position and a locking position. This securing spring serves to open and close a recess which is disposed in the coupling part and which represents the bearing recess for the wiper arm pivot bolt. The securing spring is prestressed toward the head strip of the wiper strip, so that to displace the spring, the friction between the rubber and the spring has to be overcome. On the one hand, it should be easy for the user to slide the spring, for instance when changing wiper blades, but on the other, the spring must reliably close the bearing recess in the channel wall during wiper operation, so that the wiper blade cannot become disconnected from the wiper arm unintentionally. These two mutually contradictory demands cannot both be met equally well.
In the wiper blade of the invention, securing the pivot bolt and the mounting channel is assured, viewed perpendicular to the window, by the channel wall of the other partial channel that discharges into the bearing recess. The securing shoulder of the wiper arm prevents the pivot bold from creeping out of its bearing recess during wiper operation, in cooperation with the counterpart shoulder of the wiper blade.
To achieve especially good securing of the pivot bolt in its bearing recess, the other partial channel, opening into the bearing recess, extends in a plane that is at least approximately parallel to the window.
If the one partial channel, having the insertion opening, extends in a plane perpendicular to the window, then the wiper blade can be joined to the wiper arm in a simple way.
If furthermore the two partial channels form an angle xcex1 of 90xc2x0 with one another, the result is an especially reliable connection between the wiper arm and the wiper blade.
In a further development of the invention, the coupling part is made from an elastically yielding plastic, and the mounting channel in its width has a partial constriction, whose width is less than the diameter of the pivot bolt. As a result, securing against unintentional separation of the wiper blade from the wiper arm is achieved when the wiper arm is hinged away from the window, because the pivot bolt is snapped into the bearing recess of the wiper blade, with the constriction being temporarily spread open.
An especially compact design of the wiper apparatus is obtained if the securing shoulder of the wiper arm is disposed between pivot bolt and the guided end of the wiper arm.
Advantages in terms of production are obtained if the counterpart shoulder of the wiper blade is embodied on the coupling part.
In a further feature of the invention, the wiper arm has a U-shaped cross section on its free end, the two legs of which U extend, fitting over the longitudinal sides of the coupling part, from the base of the U to the window, and the ends of the pivot bolt are retained on the two legs of the U. The result is especially good wiper blade guidance during wiping operation.
In a further development of the concept of the invention, the securing shoulder of the wiper arm is embodied on the jacket face of a support bolt, which is disposed with spacing from the pivot bolt and is retained with both of its ends at the two legs of the U of the wiper arm. By this provision, complicated and expensive production or mounting steps can be omitted.
If furthermore the counterpart shoulder of the wiper blade is embodied on the side wall, remote from the pivot bolt, of a transverse groove that is disposed in the coupling part and is open on the side of the coupling part remote from the window, further simplifications in production are obtained in terms of the embodiment of the wiper blade counterpart shoulder.
So that the securing shoulder of the wiper arm, during the pivoting motion of the wiper blade, the axis of the pivot bolt can always cooperate with the counterpart shoulder of the wiper blade, the transverse groove extends from its opening to the groove bottom along a circular path whose radius corresponds to the spacing between the pivot bolt and the support bolt. As a result, the hinge connection between the wiper arm and the wiper blade is kept free of play at all times in every operating position of the wiper apparatus, and the pivot bolt bearing is relieved.
To achieve an especially low structural design for the wiper apparatus, with the attendant advantages, the coupling part is disposed on the band side, remote from the window, of a band-like elongated, spring-elastic support element for the wiper strip. The wiper strip itself is located on the other, lower band side of the support element, facing toward the window.
Further advantageous refinements and features of the invention are given in the ensuing description of an exemplary embodiment shown in the associated drawing.